Automatic fluid control and vacuum device



Aug. 13, 1935. c. H. EASTMAN 2,011,476

- AUTOMATIC FLUID CONTROL AND VACUUM DEVICE 7 Filed Sept. 12, 195:5 2 Sheets-Sheet 1 Max-w Aug. 13, 1935. c. H. EASTMAN AUTOMATIC FLUID CONTROL AND VACUUM DEVICE 2 Sheets-Sheet 2 Filed Sept. 12, 1955 any,

Patented Aug. 13, 1935 "Charle's H. Eastman, Boston, Mass.,'assignor to Eastman Heat Control Corporation, Boston,

Mass, a corporation of Massachusetts Application September 12, maase r ial o. 639,073

. 14 Claims.

This invention relates broadly to an automatic fluid control device and particularly to a combi-- nation pressure and vacuum control device.

In certain respects the device'ofthisinvention is similar to devices or my invention for which I have obtained United States Letters Patent No; 1,505,381, August 19, 1924 and No. 1,530,485, March 24, 1925, to whichreference may be had for a further description of the'u'ses and functions of this type of automatic fluid control device.

The control device of this invention is particularly adapted to be used in connection with an operating instrumentality' for fuel oil supply feeds, gas, air, steam, pressure reducing valves,

release valves, or any such instrumentality' requiring a substantially uniform -low pressure, which device when installed requires no attention as it automatically regulates the pressure to an accurate and'dependable degree. k

The invention more particularly relates to improvements in the above-mentioned patented de vices whereby to insure the continuity, accuracy and smoothness of their operation'and is' especially adaptable to heating systems that are supplied with steam purchased from district heating companies or a central heating plant, and to lowpressure and vacuum heating plants. When steam is purchased a needless waste exists in most cases due to the humanequation. The main steam supply valve is hand operated and opened partly; The regulating of this valve is entrusted to an individual whose other duties are numer ous. Consequently, the amount of steam delivered to the building, at most times, is either inadequate or in excess of the demand with cor responding dissatisfaction. This conditionywith improper control of the steam pressures, or vacuum, not only results inexcessive cost of opera-.

demand by consumers and sellers of purchased steam for a system of control that will accomplish the following results:l. Automatically open a control valve "thereby admitting suflicient steam to the heating system, at a steady uniform pressure or-vacuum, and automatically close this valve when adequate heat has'beensupplied to meet the requirements, and 2,,an. automatic, accurate anddependable means for controlling the steam pressure or vacuum, said means being capable of operating above and below atmospheric pressure to maintain auniform steam pressure or vacuum in the heating system without human (or. 137 i53)' equation, despite varyinginternal conditions or outside weatherfchanges. Briefly, the control device of thisinvention comprises a closed hollow casing having an expandible and contractible actuating member mounted therein in a manner to divide the interior of the casing into pressure and vacuum compartments, Aweighted reciprocatory rod is mounted upon the actuating member and extends outwardly through the casing for connection to an operating instrumental ity. Within the pressure compartment beneath the actuating member, a piston is mounted for vertical movement and in certainconditionsof operation to lift the actuating member. A liquid seal provided between the piston and easing normally extends upwardly to a, predetermined height within the piston. The vacuum compartment isconnected by suitable piping withsuitable vacuum creating instrumentalities, including. the vacuum return line of the steam-heating system and with the lowpressure'side of saidsteam supply main. The fluid, the pressure of; which. is to be controlled, is-piped into the piston above the liquid seal, whereby it functions to move the piston within the pressure compartment of ,the casing and thereby control the operating instrumentalities. a j c v, I The object of the invention is to providea single unitary device embodying therein a mechanism adapted to utilize either pressure or vacuum in its operation and also constructed and arranged to automatically change from pressure to vacuum, and vice versa, without the necessity of anybody being present ,atthe time of said change, thereby eliminating the human equation which is at pres ent required for-handling separate devices.

Another object of the invention is to provide a device of the character set forthwhich can be installed to operate at a predetermined pressure or below atmospheric pressure, said devicebeing simple in its construction and eiiicient in its operation. In this device if the steampressure; is set at one-half pound, and is changed to vac uum, the same weights will allow a setting pre determined in inches of vaouum without altering their position. v

The invention contemplates in itsconstruction the utilization of certain air Vents and check valves positioned in thesystem as may be required .for the purpose of increasing the efficiency of the following specification and particularly as p'ointed u u i t e d ms the eof-,4

an air vent, or relief valve,.used at several places 7 in the device.

- Fig. 6 is a view similar to Fig. 2, but illustrating a modified embodiment of the invention.

Fig. 7 is a view similar toFigs. 2 and 6 illustrating still another modified embodiment of the invention.

Likenumerals referto like parts throughout the several views of the drawings.

In the drawings, referringparticularlyto Figs. 1 -to-5 inclusive, I is a casing preferably cylindrical and closed at its opposite ends by a top H and bottom F2.- Inside the casing w a piston I3 is provided which is open at the-bottom and closed by a' topfl l fast thereto. A suitable quantity of water or other suitable liquidl5 i's provided at the bottom of the casing H! toconstitute a seal between the piston l3 andthe casing and this.

seal normally rises to. the levelindicated by the line AA, Fig.1, both within the piston and in the space between said piston and the casing. The casing 1 0 is provided-witha-gage l6 which registers the pressurein the piston in a manner'well known tothose skilled in the art. I'he piston I3 is provided with a plurality of anti-friction rolls l'I- located adjacent tothe top thereof and a plurality of other anti-friction rolls 18 located adjacentto the bottom thereof, all of which are adapted to contact withthe interior of the casing HI and constituteanti-friction guide members for the piston duringits-reciprocatorymovemerits in the casing.

Projecting upwardly from member l2 of the casing is a conical standard I9 which projects into the bottom of the piston i3 and terminatesat the l-iquid level A pipe 20 is mounted at its lower endin a separator 21 and extends from said-separator upmrdlythrough anair chamber 22 provided theinterior of the standard- 19- andterminates at its upper extrem-ity in the topportion of saidstandardg Another pipe Zifl'whicl'r ineffect constitutes a continuationof the pipe 20, is mounted in the top portion of the standard I9 in alignment witl'r the pipe 2'0 and, terminates at its upperend within the piston l3 a substantial-distance above-the normal level of the liquid constituting the seal. Theupper extremi-tyof the pipe 23' is open and said pipe is provided with ports 24 which are located just'above the upper extremity of thestarrdard l9, whereby the height of the: liquid,

comprising the: seal isregulated as AA. V V

' A standard 25 is secured at the topthereof 'to the bottom portion of the separator 2i while the at the level bottom portionof said standard is secured to a suitable'pedestal 26-.

Mounted at the top of the gage 1'6 and com-'- municating with the interioroi the casing l0 through the piping instrumentalities which con-' stitute the liquid gage is a; combined filling plug and air vent 21. 'I'his-mem-berfwhich-"is illusedraw Para trated in detail in Fig. 5, serves' to provide a vent for the interior of the casing I0 and when it is removed from its pipe connections to the container, the liquid constituting the seal may be admitted to the interior of the casing through these pipe connections.

The separator 2| has a drain pipe 28 communieating therewith which'is utilized as a means for discharging excess condensation which may accumulate in the bottom portion of saidseparator. A valve 29 is provided for the purpose of permitting this condensation to pass into the drain pipelfl, said valve being pivotally attached at 30 to a cover plate 3| forming a part of said separator. The. valve 29, is actuated by means of a float 32 which rises in a well-known manner when the condensation at the bottom of the separator reaches a predetermined level. i

A check valve 33 is attached tothe separator 2| by means of a pipe 34 and communicates-with the chamber providedupon the interior of theseparater sothat if a vacuum should form in the piston l3 it willbe broken by air entering through this valve- An air vent or relief valve .35 is also provided in. the pipe connection 34, to the interior of the separator H for the purpose of permitting the escape ofdead air from .said separatoraud connected passageswhen initially deliveringsfluid to the piston to start the operation of the control device. Q V 1'.

Mounted in the upperportion of the casingqlfl and secured. to the top member H thereof in any suitable manner is anactuating member 36 embodying therein-a bellows 31 of well-knowncohstruction and a rigid plate 38, the latter being, secured in any suitable manner at the lower extremity of said bellows 31. Thespa'cewithin the bellows 31. andabove the plate 38 constitutesa vacuum compartment 39. The adjacent interior portion of the casing H! upon the exterior of the actuating. member andin which the piston 13 reciprocates will be. hereinafter referred toas an atmospheric pressure compartment 40.. l a A rod- Hfis rigidly secured to the plate 38 and extendsupwardlytherefrom through the vacuum compartment39 and outwardly through the top member it of the casing 10, passing througha suitable stuiling box 42 provided in the top member H. Suitable bearings 43 and 44 are provided mounted-as desired upon the top casing member ii and engaging the'rod M A check valve .45-and vacuum gage 46 of well-known construction are securedto pipe connections 41 which are secured to the top member ll of thecasing III and communicate with the vacuumgcompartment 39; ,A pipe is-also connected to thetop member I l of thecasing. Ill and communicateswith the vacuum compartment'39l and said pipe is connected in a Well-knownv manner with. a return line 49 which leads from the heating instrumentalities of a building as, for example, the radiators thereof to a vacuum pump 50 well known'in; the art, and

operated by means of an electric or other motor- 5 I.

A hand. operated valve 521s provided for the pipe I 48. .A valve 48Lis also provided for the; pipe 48 adjacent to the topmember l I of the casing it in order that air. at atmospheric pressure may enter the vacuum compartment 39. at all timeswhen the vacuumv creating. instrumentalities are not func- 2| and; communicating with the interiorlthereo-f: and also with the interior of the piston l3 through pipes 20 and'23 is a steam supply pipe 53. This steam pipe 53 may lead toany suitable source of steam supply such, for example, as a steam main or boiler. In this instance the pipe is illustrated as being connected to a steam supply main 54 havinga balance pressure valve 55 of..wellknown construction provided therefor, thereby dividing said main :intoa high-pressure sideifit and a low-pr ssure side 57. The valve 55 is pro.- vi'ded with an operating handle 58; The steam pipe 53 extends from the separator 24 upwardly beside the casing l0, and at a point at;a level above the top H of said .casing has a throttle valve 553 of well-known construction inserted therein. At a point in the steam pipe 53 between.

the throttle valve 59 and separator 21 a strainer Gil of well-knowns construction is inserted. A

check valve 6| is'iturthermore inserted in the movement between said'lever and pin during the upward and downward movements of the lever. A mercury switch 65 of well-known form is secured tothe lever 62 and is electrically connected bymeans of wires .61 and 63 with the electric motor 59. The reciprocatory movement, therefore, of the rod 4], as hereinafter to be explained, will automatically causethe throttle valve 59 to be actuated and the motor 5| to be energized.

The balance pressure valve 55 is operatively connected to the rod 4| to be actuated thereby through the medium of a lever 69 and adjustable connecting rod 10, the latter operatively connecting the lever '39 with the handle 58 of. the pressure valve E5. The lever 69 is pivotally connected at H to a bracket H which is mounted upon the top casing member ii. The lever iii? is operatively connected to the] collar iii of therod 4! through the medium of the pin 63 which projects through a slot 73 provided in the lever 69, see Fig. 4. Weights 14 of suitable size and number. are suspended from the outer extremity orfree end of the lever 69 by means of, a rod' '55 and the actuating member 36 is set-to function v at any suitable pressure desired or at the vacuum 55? point desired by varying the number of the weights suspended from the outer extremity of the lever 59. In effect a variable tension isimposed upon the actuating member 36 by increas ing ordecreasing the number of weights utilized. The vacuum pipe 48 is connected with the lowpressure side 51 of the steam supply main 54 by means oi a pipe E6, and a handeoperated valve Ti, and automatically actuated check valve'iil are interposed in this pipe I6.

The steam pipe 53 is connected with the highpressure. side 56 of the steam supply main M by means of a pipe 19 in which is interposed an automaticallyv actuated solenoid valve 80, the latter being 'electrically connected by means of wires 8| and 82 with a thermostatically actuated control device or clock mechanism 83 which may be. located at any desired location in the building and which may be utilized for causing the solenoid valve to be actuated for the purpose. of opening or closing this valve. The pipeH'iS 'isconnected to the. pipe 53st a point between the throttle valve'59 and the low-pressure side 5'; of thesteam such device is operated as a pressure device. is as *folloWs:-'-Assuming that the hand-actuated valves 52 and ll of the. vacuum controlsystem have been closed and that the actuatingmember -36.has been set to function at a certain predetermined pressure by placing weights it in required number uponv the rod 215 at the outer-exs tremity of the 1ever59, and that. liquid such as Water'has been inserted in the casing i6, through theopening provided by removing the air vent or filling plug 21 until said water reaches the level indicated by the line AA, and that steam under pressure from the low-pressure side 51" ofthe steamsupply main E l-is introduced tothe interior of the piston i3through the pipe 53, separator 2i and pipes. 20 and 23; all condensation of supplyfiuidis separated and falls, being taken care of by the discharge valve 29. The liquid it. in the piston It will be forced downwardly by the. pressure of said steam and will be forced upwardly in the space between the piston I3 and The air which at that time is the casing Ii]. enclosed between the space between the piston and theacasin'g will pass outwardly from said casing to the atmosphere through the air vent 2?. This operation will continue, the piston 13 rising and,

g T A the" liquid between the walls of said piston and said casing also rising, and the liquid inside the piston descending until eventually the top member'i l of the piston will'engage the under surface of the plate 38 which constitutes a portion of the actuating member 36. A continued upward movement of the piston i3 will thereafter gradually collapse the bellows 31 of the actuat ingmember 36 and cause the rod 4! to move up-' wardly carrying with it the lever 69 which is connected to the balance valve 55 and the lev'erBZ.

whichis connected to the throttle valve 5d. The" movement of the lever 69, connecting rod 'ida'nd handle58 of the valve 55 will cause the latter to be actuated to partly close said valve, thereby allowing justenough steam to pass from the highpressure side 56 of the'steam supply main to the' low-pressure side 5'! thereof to carry steadily and uniformly the pressure at'which the control de-' vice is" set.. At the same time" that the balance valve 55 is actuated to reduce the steam pressure admitted to the pipe 53, the throttle valve 59 will be actuated to, alsoregulate the quantity of steam that is permitted to pass therethrough andfrom thence to the interior of the piston i3.

thus admitting less steam and causing piston to likewise return to its set position. In this way the set pressure is maintained. Steam. is prevented from entering the vacuum compartment sfigbycheck valve 18 which is closed whenpresg sure ison the system,

'ing the balance valve towards its closed position v in the piston I3 and in the casing Ill, the surphzs water thus accumulated will overflow through the If steam: isthe fluid which is being used and condensation has increased. the amount of. water drain pipe 28 as permitted so to do by the valve 29. The general operation of the device when operated as a vacuum deviceisas followsz-At this time the valve 52 or'I-l is openand the vacuum pump 50 is functioning in a 'well-known manner to maintain a pressure below atmospheric throughout the heating system or return; lines to traps on radiators, andwithin. the vacuum compartment 39 ofthe controldevice. .If. valve 52 through the entire heatingsystem. v

. is shut and valve 52 open,.vacuum will be carried is shutand valve 11 open,1vacuumwill:be carried If valve 11:

in return lines only. "Steam will be prevented from entering piston libycheckt valve 61. which is held closed'by vacuum. If the vacuum pump 50' creates more vacuum than the control device is set to carry, the bellows 31 will startto collapse on account of. the difference in pressureexerted the plate 38, the pressure in vacuum bellows being below-atmosphere, and the outside of plate 38 under atmospheric pressure as space between casing Iii and-piston; i3 is open to atmosphere at all times through air vent 21'. As the bellows 3T collapses the rod 4'! will start to rise, as hereinbefore mentioned, thereby simultaneously actuatingthe pressure reducing valve 55 to partially close the same, and also tipping'themercury switch 86' carried by the lever Gland thereby stopping the motor 5| and the vacuum pump!!! operated thereby. The vacuum pump will remain shut off until the vacuum gradually returns to the pressureior which -the control device is set, during which interval the rod H will have gradually dropped toa point which will again cause the mercury switch 66 to function to again start 7 ing main. When the steam pressure drops and vacuum is formed,.thejvalve 6 f will close and the valve [81 open.

It will be understood that the vacuum in' the heating system is carried to the steam pressure main on the low-pressure side and also to the return main so that if the vacuum is carried only on the return it isgoverned from that point and if. the vacuum is carried throughout the entire system it is governed at a point near the reducing pressure valve.

At night. when, no steam is in use the solenoid valve is automatically actuated by means of its controldevice 83 to permit relatively highpressure steam to be delivered from the highpressureside 56 of the steam main into the pipe 53 between the throttle valve and the check valve 5|. This high-pressure steam will auto-- of the solenoid valve in a well-known-manner by amine means of its control device 83,the1presswe is removed from the. piston l 3-and the latter will. gradually tail to its normal position, thereby automatically opening the balance valve .55.. Steam from the low-pressure side. 51 of the steam will: then. again be admitted. to the piston; l'3 causing the pistonito again rise until the 1 amount of pressureior which the device has been set has been reached; This last-described mechanism tfunctions inv exactly the {same manner whether the'device is used as a pressure or. a vacuum device. The check valve 45 functions to relieve the vacuum compartment 33 of any pres the actuating memberyafl functions in exactly the same: manner as does the actuating member of the preferred construction, a space 86 above the diaphragm constituting a vacuum compartment and a sp'aceal within the casing beneath the. diaphragm 85 constituting an atmospheric pressure compartment. V

In Fig. 7 another modified embodiment of the device is illustrated in which an actuating mem ber 88 is constructed'in the form 01 a corrugated diaphragm 1 89 The space within the casing above the diaphragm 89 constitutes a vacuum compartment 90 and the space within the casing k0 beneath the diaphragm-89 constitutes an atmospheric pressure compartment 9| In this embodiment of the invention apiston I3 is loosely positioned at the top thereof within a guide member 92 which is carried by the diaphragm as; and a tubular member 93 projects upwardly from said guide-member 92 through the top member lit of the casing Ill forjthe purpose of transmitting motion from the diaphragm 89 tothe instrumentalities located upon-the exterior of the casing. In this structure, furthermore, air at atmospheric pressure enters the pressure compartment SI through thetube 93 and the air: vent 21 utilized: in; the other embodiments .of the in.-

1 r so vention may be eliminated.

Iclaim: J 1. An automatic fluid control device comprising, in combination a casing, an 'e'xp andible and 1 contractible actuating member mounted. therein;

a reci'procatory member'also mounted within said casing. independent of said actuating member but adapted to communicate motion. thereto, apressure fluid supply'pip'e, a valve thereior, I

to convey pressure fluid from said supply pipe to said reciprocatory member to actuate the same, a. valve for said last-named means, and a member carried by the actuating member'and' projecting outwardly through: the casing and operatively connected to both of said valves,whereby both v 1 of the valvesmay be operated. V V

2. An automatic fluid control device compris ing,' in combination-acasing, a bellows mounted in said casing, a reciprocatory member constituting a float also mounted within said casingindependent of said bellows but adaptedjtolcommunicate motion theretoya pressure fluidsupply pipe, a valve therefor; liquid in said a forming a seal between the casing and float, means; to convey pressure fluid; fromsaid supply pipe to said. reciprocatory memberto actuate the same, a valve for said last-named means, and a memberv carried by said bellows and projecting outwardly through the casing 'and operatively 'projecting outwardly through the casingand:

operatively connected to'bo'th of said valves whereby both of the valves maybe operated; I

4 Anautomatic fluid control and vacuum device comprisingin-combination; a casing, a bellows mounted wifhin'said casing and co-oberating therewith to form a vacuum compartment, a piston constituting. a float within the casing independent of said bellowsbut adapted to communicate motion to said bellows, liquid in said casing forming as eal 'between-the casing and piston, means to convey pressure fluid to said piston to actuate the same and thereby contract the bellows, a. vacuum pump 'to reduce the pressure within said vacuum compartment below atmospheric, whereby the bellows will contract inde-' pendently of the action of thepistoni means to impose a variable tension upon said bellows, and a member carried by thebellows and projecting outwardly through the casing, whereby said vac uum pump and other instrum'entalities upon the exterior of the casing maybe operated. a

5. An automatic'fluid control and vacuum dedevice comprising in co mbination, a casing, an expandible and contractible 'actuating'member Within said casing and co-operating therewith'to" form a vacuum compartment, "a'reciprocatory member constitu ing a float within the casing independent of said actuating member butadapted to communicate motion thereto, liquid in said casing forming a seal between the casing and reciprocatory member, means to convey pressure,

fluid to said reciprocatory member to actuate the same, an electrically actuated vacuum pump to reduce the pressure within the vacuum compartment below atmospheric, whereby the actuating member will function independently of the action of the reciprocatory member, and a member carried by the actuating member and projecting outwardly through the casing and operatively connected to a switch for said vacuum pump whereby the operation of the latter is controlled.

6. An automatic fluid control and vacuum device comprising, in combination, a closed hollow casingan expandible andcontractible actuating member within said casing dividing the interior thereof into pressure and vacuum compartments, a piston in said pressure compartment independent of said actuating member but adapted to communicate motion thereto, liquid in said casing forming a seal between the casing and piston, means to convey pressure fluid to the interior of saidpiston above the liquid therein, a vacuum pump to reduce the pressure within the vacuum compartment below atmospheric, whereby the actuating member will function independently of the action of the piston, an electric switch for said vacuum pump, and a member carried by the actuating member and projecting outwardly may. be operated.

'7. An automatic fluid controljand vacuum vice comprising, incombination, a closed hollow casing, an expandible and contractible; actuating member within said casing dividing'the same into pressure and vacuum compartments, a-piston in said pressure compartment independent oi. said ctuating member but adapted to communicate motion thereto, liquid in said casing forming a seal between the casing andpiston, means to convey fluid under pressure to the interior of 52nd,

iston above the liquid therein, means including a vacuum pump to reduce the pressurewithin the vacuum compartment below atmospheric, whereby the actuating member will functicnindepend ently, of the action of the piston, a rod carried by the actuating member and projecting outwardly through the casing-and operatively connected to said vacuum pump, whereby the operation of the latter is controlled, and other means connected to said rod for controlling the flow of said pressure fluid to the piston. r I

8. An automatic fluid control andvacuum device comprising, in combination, a closed hollow casing, a bellows witlm'n said casing and'co-oper ating therewith to form pressure and vacuum compartments, a piston constituting'a flo-atin' said pressure compartment independent of the bellows but adapted to collapse said bellows, liquid in said casing forming a 'seal'between the casing and piston, means to convey pressure fluid to the interior of said piston above the liquid there'- in, an. electrically actuated vacuum pump to-re-;

ducethe pressure within thebellows below atmospheric, a switch therefor} means to admit air at atmospheric pressure to the vacuum compart ment when operating'under pressure and to ex' elude-said air: when operating undervacuum, and a. member carried by the bellows and projecting outwardly through th casingand operatively' connected to said switch, whereby the operation 1:5 9. An automatic fluid control and vacuum de of the vacuum pump is controlled. H

vice comprising, in combination'a closed hollow operating therewith'to form pressure and vacuum compartments, a piston constituting a float insaid casing independentof but adapted to col lapse said'diaphragm,'1iquid in said casingform inga seal between the casing and'piston, means to convey pressure fluid to the interi r of said piston above the liquid therein, means including a vacuum pump to reduce the pressure within the vacuum compartm nt below atmospheric, whereby the diaphragm is actuated independently of the action of the piston, a member carried by the diaphragm and projecting outwardly through the casing and operatively connected to-said vac uum pump, whereby the operation of thelatter is controlled, and other means actuatedby said diaphragm for controlling the flow of pressure fluid to the piston. 10. An automatic fluid control and vacuum device comprising, in combination, a closed hollow casing, a bellows within said casing and co-oper 7 through "the casing and operatively connectedto saidswitch whereby the'vacuum pump and other: instrumentalities upon the exterior of the casing casing, a diaphragm within said casing and cof ating therewith to form pressure and vacuum compartments, a piston constituting a float in said pressure compartment independent'of but adapted to collapse said bellows, liquid in said casing forminga seal between the casing and p is ton, means to convey pressure fluid to the interior of said piston above the liquidtherein, a

vacuumpump to reduce the pressure within the bellows below atmospheric, whereby said bellows isactuated independently of the action of the piston, a member carried by the bellows and projecting outwardly through the-casingand operatively connected to said vacuum pump, whereby the operation of the latter is controlled, other.

means actuated by said bellows for controlling the flow of pressure fluid to the piston, and means to place a variable tension on said bellows whereby thelatter will function at variable pressures.

11. An automatic fluid control and vacuum device comprising, in combination, a casing, an ex-. pandible and contractible actuating member mounted within said casing and co-operating therewith to form pressure and vacuumjcompartments, a piston within said pressure compartmentadapted'to communicate motion to said actuating member, means toconvey pressure fluid to said piston to actuate the same, a throttle valve for said last-named means having an operating lever embodied therein, means to reduce. the pressure within the vacuum compartment below atmospheric, a switch mounted upon said'opcrating lever and electrically connected tosaid pressure reducing instrumentalities, whereby the latter areactuatedautomatically by the'movcment of the operating lever, and a member carried by the actuating member andprojectingout- 'wardly through the casing and operatively connected to said lever whereby the operation of the pressure reducing instrumentalities is controlled.

12. An automatic'fluid control and vacuum device comprising,v in combination, a casing, an expandible and contractible actuating member mounted within said casing and co-operating j therewith to form pressure and vacuum compartbodied ther ein, means to reducethe pressure in the vacuum compartment below atmospheric, a switch mounted upon said operating leverand electrically connected to saidpressure reducing instrumentalities, whereby the latter are actuated automatically by the movement of the operating lever, and a member carried by the actuating member and projecting outwardly through the casing and operatively connected to said operating lever and to said balance valve whereby the operation of the pressure reducing instrumen-' talities and the flow of pressure fluid through the supply pipe is controlled.

13. An automatic fluid control and vvacuum device comprising, in combination, a closed hollow casing, a bellows within said casing and co-oper ating therewith to term pressure and vacuum;

compartments, a said pressure oompar-tment adapted to oollapse said bellows, liquid in said casing forming a-seal between the casing and piston, a pressure fluid supply pipe, a balance valve for said pipe dividing the same into a high-pressure side and a low-pressure side, means to conveylow-pressure fluid from said supply pipe to the interior of said piston above the level of the liquid therein, a throttle valve for said lastnamed means having anoperating lever embodied therein, means to reduce the pressure within the,

bellows below atmospheric, a switch mounted upon said operating lever and electrically con nected to said pressure reducing instrumental ities, whereby the latter are actuated automatically by the movement of the operating'lever, a

membercarried by1the bellows and projectingv outwardly through the casingand operatively connected to said operating lever and to said balance valve, whereby the operation of ithepressure reducing instrumentalitiesand the flow of pres-' sure fluid-through the supply pipe'i-s controlled,

and means toimpose a variable tension upon the the bellows whereby the latter will vfunction at variablepre'ssures. 3 o 14. An automatic fluid control and vacuum devicecomprisinggin combination, a closed hollow casing, ,a bellows within said casing and co-oper ating therewith to form pressure and yacuum compartments, a piston insaid pressure compartment adapted to collapse said bellows, liquid in said casing forming a seal between the casing and piston, apressure fluid supply pipe, a balance valve for said pipe dividing the same into a highpressure side and a low-pressure side, means to convey low-pressure fluid from said supply pipe to the interior of saidpistonabove the level of the liquid therein, a throttle valvefor said, last-named means having an operating lever embodied there in, means to reduce the pressure within the bel-x lows below atmospheric, 9. switch mounted upon said operating lever-and electrically connected to said pressure reducing instrumentalities, whereby the latter are actuated automatically by the movement of the operating lever, a member carried bythe bellows and projecting outwardly through the casing and operatively connected to said oper'ating lever and 'tosaid balance valve, whereby the operation of the pressure reducing instrumentalities and the flow of pressure fluid through the supply pipe is controlled, means to impose a variable tension upon the bellows whereby the latter will functionat variable pressures, means to convey high pressure fluid from the supply pipe to the piston, a valve therefor, and means to automatically control the actuation of said lastnamed valve whereby the piston is actuated to open and close the balance valve at predetermined times; a CHARLES H. EASTMAN. 

